The present invention relates to a stem mechanism, and more particularly to a stem machanism for a watch of exceedingly thin size to eliminate the overall watch thickness.
In the conventional type stem mechanism for a watch, the intermediate portion of the winding stem has a square section to engage with the sliding pinion, whereby the stem and the sliding pinion overlap planly and the stem mechanism has the thickness of the stem plus the sliding pinion. As the result, a wheel train turned by the stem and the sliding pinion is inevitably arranged to add to the thickness of the timepiece.